- Email: [email protected]
Cockroach sensitization in laboratory workers
Dan I?. Stainberg, M.D., David I. BsrnsWin, M.D., Joan S. G Larry Arlian, Ph.D.,* and I. Leonard Samstain, M.D. Cincinnati
and Dayton,
er, Ph.D.,
Ohio
Six laboratory workers who were exposed to American cockroaches (AC) and German cockroaches (GC) while they were pe$orming immunologic experiments were evaluated for cockroach hypersensitivity. Prick skin testing and UAST were performed with whole body extracts (I :20 wtlvol) of AC, brown-banded (BB), and GC species as well as hemolymph and fecal (F) extracts of AC. Three of six workers reported work-related nasal and ocular symptoms associated with xenografting and bleeding of cockroaches. All three symptomatic workers exhibited cutaneous reactivity to at least one cockroach antigen. Elevated RAST binding was observed in one of the three symptomatic workers. A nasal provocation to AC was positive in the most symptomatic worker at a provocative dose of 3.2 X IO’-’ mg causing a 50% decrease of nasaljow rate from baseline. After pretreatment with nasal cromolyn, the provocative dose causing a 50% decrease from baseline increased to 2.6 X IO-’ mg. Nasal provocation with the same concentrations of AC were negative in two skin test negative subjects. RAST-inhibition studies demonstrated cross inhibition of the serum-spec$c IgE binding to AC-hemolymph by AC, GC, and BB whole body extracts. However, specific IgE binding to AC-F was inhibited by AC-F and AC but not by GC or BB whole body extracts, suggessting there was greater specificity of the F allergens. This study demonstrated that cockroach allergens elicit IgE-dependent upper respiratory sensitization in the workplace. (J ALLERGY CLIN IMMUNOL
1987;80:586-90.)
Cockroach emanations have been recognized as important inhalant allergens. ’ The most common cockroach species in North America are the GC (Blatella germanica) and the AC (Periplaneta americana). In 1964, Bernton and Brown’ demonstrated direct cutaneous sensitivity and positive Prausnitz-Kiistner responses to cockroach allergens. Subsequent studies have also documented respiratory sensitization to cockroach allergens.3-‘0Kang and Sulit” noted a high prevalence of cutaneous reactivity to cockroach allergens among urban patients with asthma. The same
Abbreviations
AC: H: BB: GC: F: PD,:
used
Americancockroaches Hemoiymph Brown-bandedcockroaches Germancockroaches Fecal Provocative doseof allergenrequiredto cause a decreaseof SO%of nasalflow rate from baseline
Tm: T&ebrio
molitor
investigators subsequently documented the presence
of both immediate- and dual-phase bronchoconstrictive responsesin patients with extrinsic asthma after bronchial challenge with cockroach allergen.3, 5 This article presents clinical and immunologic stud-
From the Division of Immunology, Department of Medicine, University of Cincinnati Medical Center, Cincinnati, and *Department of Bioiogical Sciences and F’bysioiogy, Wright State University, Dayton, Ohio. Received for publication Nov. 20, 1986. Accepted for publication April 18, 1987. Reprint requests: David I. Bernstein, M.D., University of Cincinnati MedicaI Center, Division of ImmunoIogy, M.L. #563, 231 Bethesda Ave., Cincinnati, Ohio 45267.
ies on cockroach-labora@ty workers, some of whom developed nasal and ocular Sykes assc&@ed with work-related exposure to cockroacbs and I@mediated sensitization to cockroach allergens.
Thestudygroupconsistedof six laboratoryworkersfrom the Departmentof BiologicalSciencesat the WniGersityof Cincinnatiwho were performingexperimental&&es on cockroaches and represented all the workers in the Iabomtory who wereregularlyexposedto AC agdGC. The workers reportedno other signific~t exposureto ctMzoac&es outside the workplace or at home. Exposureto feca&nat&al
VOLUME NUMBER
BfJ 4
Cockroach
sensitization
occurred in those workers who also participated in feeding and maintenance of cockroach colonies located in a separate storage room. There was further exposure to AC-H when animals were exsanguinated for in vitro cellular and humoral studies. In addition, xeno- and allografting experiments were performed with BB and GC. Because this laboratory was primarily involved with the investigation of cockroaches, none of the six workers had an opportunity for exposure to other laboratory animals. An informed consent was obtained from all subjects. An occupational history was obtained on all six workers by physicians. The duration of laboratory exposure and latency period before onset of symptoms was recorded. Information was elicited regarding possible work-related ocular, nasal, and bronchial symptoms. A complete personal and family atopic history was also obtained.
TABLE I. Results of symptoms, skin tests, and RAST in cockroach-exposed and nonexposed laboratory workers
Immunologic
NA
studies
Cutaneous prick testing was performed in all six exposed and eight IaboratoIy workers not exposed to cockroaches. Pure culture extracts of AC, GC, and BB whole bodies were prepared by Dr. Larry Arlian, Wright State University, Dayton, Ohio. Whole insect bodies were dried in a dessicator with anhydrous calcium sulfate for 48 hours and then extracted in phosphate-buffered saline, followed by sterilization through a Millipore filter (Millipore Corp., Bedford, Mass.).16 All skin test reagents were prepared at a final concentration of 1: 20 wt/vol. H and F extracts were prepared in a similar manner. Protein content was determined by the Bio-Rad (Bio-Rad Laboratories, New York, N. Y.) method with bovine gamma globulin as a reference protein. Prick testing was also performed with commercial extracts of dust mite, ragweed, grass, and cat allergens (HollisterStier Laboratories, Spokane, Wash.) to define atopic status. A prick test wheal that measured 3 mm greater than the saline control wheal accompanied by flare was considered a positive skin test. Specific IgE to cockroach allergens was measured by a modified RAST assay.” RAST results were expressed as percent binding calculated by dividing counts per minute bound by the worker’s serum by counts per minute of total 9-labeled anti-IgE added multiplied by 100. RAST-inhibition studies were performed with serum that exhibited the highest RAST binding to cockroach.” Equal volumes of test serum were incubated at 37” C for 2 hours with successive tenfold dilutions of each cockroach extract and centrifuged at 1500 X g for 15 minutes. The upper two thirds of the supematant was removed and incubated with AC-H coated and AC-F coated methylcellulose disks followed by the addition of ‘2SI-labeledanti-IgE. The percent of RAST inhibition was calculated as follows: 1 _ cpm bound by preabsorbed sample x 100 cpm bound by nonabsorbed sampleI [
Nasal-challenge
study
Dose-response nasal-provocation studies were performed with anterior rhinometry. A saline control challenge was performed before allergen challenge. The beginning dose
Worker
No.
1 2 3 4
5 6
Control subjects (N = 8)
Symptoms
Nasal, ocular, and palatal Nasal, ocular Nasal, ocular None None None None
Skin
test
587
RAST
Pos
Pos
Pos pas* pas* Neg Neg* Neg
Neg NA Pos Neg NA Neg
- not available because subjects refused venipuncture; pas = positive; neg = negative. *Cutaneousreactivity to inhalantaeroallergens.
was delivered by nasal instillation of 0.05 ml of solution containing 5 X loo3 mg based on weight per volume of the AC whole body extract. Nasal flow rate was measured before and after challenge with a Connell (Nasal Diseases Study Center, Englewood, N. J.) anterior rhinometer and expressed in milliliters per second at a constant inspiratory pressure of - 1.5 cm H,O. The same nostril was instilled every 5 minutes with increasing tenfold concentrations of AC until a positive response or a final concentration of 1.O mg/ml wt/vol was achieved. The best flow rate of three inspiratory maneuveF was recorded, and a fall in nasal patency of 50% from baseline saline control was considered a positive challenge. The cumulative PD,, was determined by extrapolation from a dose-response curve. Nasal challenges were also performed on two control subjects with no cutaneous reactivity to cockroach allergens.
RESULTS Clinical evaluation Three of the six laboratory workers described the immediate onset of nasal stuffiness, runny nose, and sneezing accompanied by ocular symptoms and itching associated with cockroach exposure (Table I). These symptoms primarily occurred during bleeding and xenografting experiments. None of the workers described wheezing, chest tightness, cough, or shortness of breath.. Of the three symptomatic workers, only one (No. 3) gave a prior atopic history consistent with ragweed and grass pollenosis and exhibited cutaneous reactivity to at least one inhalant aeroallergen. The mean latency period before onset of work-related symptoms was 6 months. The history of the most symptomatic worker (No. 1) is presented below. C. M., a 24-year-old white female research assistant,had worked in the laboratory with cockroaches for 1*/2years. Approximately 1 month after beginning work, she noted the
588
Steinberg
J. ALLERGY
et al.
CLIN. IMMUNOL. OCTOBER 1987
100 90 80 70 60 50 40 30 20 10
.OOl
.Ol
0.1 rngtml
InM&Wng
1.0 Protein
FIG. 1. RAST inhibition studies (worker No. 4) of specific IgE binding to AC-X d&s. Inhibition wss achieved by AC whole body and AC-H as well as whole body extracts of GC, BB cockroach. and a beetle species, Tm.
TAW$1. MST binding nonexposed workers
worker
No.
1 4
Control subjects
results
to various
cockroach
allergens
in two workers
AC whole body
AC-H
AC-F
6.0* 5.6* 2.5 r 0.35
2.8 8.6* 2.1 k 0.40
5.1* 10.1* 2.4 +- 0.60
and eight
2.6 6.2* 2.4 k 0.60
2.5 1.7 2.4 ” 0.40
(N = 8) *Significant RAST binding is 3 SD above the % of nonexposed control subjects; results presented in -C SEM.
immediate onset of ocular itching, nasal stuffiness,sneez-
ing, and pa&d itching while shewasfeedingand transporting cockroaches. These symptomswere alsonotedin the lahoratery whiie shewas performingexperimentson animahand resolvedcompletelylater at home,on weekends,andon vacation. Subsequent pretreatmentwith intranasalcrornolyn sodiumattenuatedher work-relatednasal andocularsymptoms.
There were four workers with cutaneousreactivity to eo&roa& a&@~. AII three symptomatic workers exhibited positive skin tests to one or more of the cockroach miqents (Table I). Although worker No. 4 was asympmmatic, he exhibited cutaneousreactivity to four of five cockroach allergens as well as common inb&ot aer&Iergens . One of three symptomatic ver-
SW two of three asymptomatic workers had positive skin teststo common inbahmt~~~~~e~~~~i~~nt with their personal atopic histories. Two or more cutaneo~ respor~ses to the ,~MMI of cockroach allergens were observed in the f&r -cutaneousreactors. Worker No. 1 exhibit& p&&e skin tests to all cockroach &lqps. Prick teets to CL+&-
roiich allergens were neg&ve in eight Iworkers not exposed to cockroaches. Two of four i~~Svi&ds with eutllllaaus ~~~t-rVity to cockrmh e?&ibixed (Table II) to cockmach W&XFS >3 SD above the mean of eight subjects. As presentedin T&@$I, hibited elevated RAST X-F (5. E%), W&err exhibited si~~t R&ST k&xdieg to &fiw of &vi
VOLUME NUMBER
80 4
Cockroach sensitization
533
100 90 60 70
AC-F
60 50 40 30 20
10 .Ol
1.0
0.1
mg/ml Inhibiting
Protein
PIG. 2. RAST inhibition studies (worker No. 4) of specific IgE binding to AC-F disks. Significant inhibition was achieved by AC whole body and AC-F but not by whole body extracts of GC, BB cockroach, and a beetle species, Tm.
130 120 110 100 e z 2
90
80
m”
70
5 I; = 2 ap
80 50 40
I
.OOl
.ch
(Cumulative
011 Doae
1.0
in mo)
Fig. 3. Nasal provocation challenge to AC whole body extract in worker No. 1. Graph shows the PDW expressed as the cumulative dose of antigen delivered to achleve’a 50% reduction in nasal airflow and the percent fall of nasal airflow from prechallenge baseline before treatment (~1 and after treatment (o--o ) with cromolyn.
cockroach allergens (AC, AC-H, AC-F, and GC). These responses in worker No. 4 could represent immunologic reactivity before onset of clinical sensitivity. RAST inhibition was performed on the serum of worker No. 4 with AC-F- and AC-H-coated allergen disks. As illustrated in Fig. 1, inhibition of RAST binding to H was achieved by all three cockroachbody extracts (AC, GC, and BB) as well as AC-F and
AC-H allergens. Inhibition was also obtained with a larval extract from the beetle Tm which belongs to a different insect order. Fig. 2 illustrates inhibition experiments on the same serum with AC-F-coated disks. There was no significant inhibition by the body extracts of GC, BB, or Tm. By contrast, there was good inhibition of RAST binding to F allergen by the homologous AC-F allergens and AC whole body but significantly less by AC-H.
590
Steinberg
J. ALLERGY
et al.
Nasal ehdsnge Nasal provocation with AC body extract was perforrned on worker No. 1 (C. M.) (Fig. 3). After instillation of AC extract, nasal patency fell 69.2% from baseline, at which ‘time the subject noted palatal itching and sneezing. The PD,, was 3.2 X low3 mg on the initial challenge. Two weeks later, the challenge was repeated after pretreatment with intranasal cromolyn. The PD,, increased to 2.6 X 10-l mg. Thus, cromolyn inhibited the nasal response to cockroach allergen. There was no significant variation from baseline after nasal provocation in two nonexposed subjects who lacked cutaneous reactivity to cockroach allergens. DJSWSSJON Previously, Bemton and Brown* reported occupational sensitization to cockroaches among entomologists and a laboratory worker. We have demonstrated work-related allergic rhinitis among invertebrate immunologists who were regularly exposed to cockroaches. Richman et aL8 reported that whole body, cast skin, egg casing, and fecal materials of the GC were allergenitally distinct by RAST-inhibition analysis. In this study, the least potent of these allergens was fecal material with whole bodies and cast skins sharing relatively, higher potencies. The same investigator found little cross-reactivity between the AC and GC extracts. In the present study, we have demonstrated that AC-H possess a broad range of cross-reactivity not only with AC-F ailergens but with a whole range of whole body allergens of different cockroach species. In addition, cross-reactivity was demonstrated between H of AC and a beetle larval antigen, Tm, of a different insect order. This finding could be due to a multiplicity of potential allergens contained in H that are common to various insect orders and species. The finding of RAST inhibition of AC-H by AC-F but lack of inhibition of AC-F by AC-H could also reflect nonspecific binding of multiple proteins to the complex AC-H. By contrast, the AC-F antigen system exhibited a more specific inhibition profile. Although AC-F allergens exhibited cross-reactivity with AC whole body allergens, there was no cross-reactivity
CLIN. IMMUNOL. OCTOBER 1987
with allergens of different species, thereby demonstrating a high specificity for F allergen. Laboratory workers have developed respiratory allergy to insects in other occupational settings.‘“. I4This study demonstrated the development of clinical sensitivity to whole body, F, and H cockroach allergens in the workplace. The clinical significance of these allergens in cockroach sensitization requires further investigation. Special thanks to Dr. Larry Arlian for preparing the cockroach extracts and to Ms. Jan Shulman for preparing this manuscript. -S 1. Kang B, Chang JL. Allergenic impact of inbaled arthropod material. Clin Rev Allergy 1985;3:363-75. 2. Bemton HS, Brown H. Insect allergy: preliminary studies of the cockroach. J AUERGY 1%4;35:%-13. 3. Kang B. Study on cockroach antigen as a p&able causative agent in bronchial asthma. J AUEROY CL@~~~NOL 1976; 58:357-65. 4. Twarog FJ, Picone FJ, S&u& RS, So J, Colten HR. immediate hypersensitivity to co&ma& isoiation and purification of the major antigens. J AUERCY CL~ hmura~ 1937,593154-60. 5. Kang B, Vellody D, Homburger H, Yunginger J. Cockroach cause of allergic asthma: its specilicity and immtlnologic profile. J AIJ.ERGYCLIN IMM~?NOL1979$3:X)-6. 6. Hulett A, Do&horn R. House dust mite and cockroach allergy in a midwestem population. Ann Allergy 1979;42:160-5. 7. Fraser BN. Cockroaches in reiation to bronchial asthma in the Durban area. S Afr Med 1979$5:637-S. 8. Ricbman P, Khan HA, lkkek$ub PC, et al. The impMtant sources of German cockroach aikgens asdetermined by RAST analyses. J ALLER~V CL~ b&mm~ &4;73:59@5. 9. Chang JL, Ryo UY, Kang B. Changes in free histamine in peripheral circulation following cockroach aatigen chalIenge in asthmatics. Mt Sinai 3 Med I984:51:197-202. 10. Kang B, Sulit N. A comparative study of prevalence of skin hypersensitivity to cockroach and house dust antigens. Ann Allergy 1978;41:333-6. 11. Wide L, Ben&h H, Johansson SGO. Diagnosis of allergy by an in vitro test for allergen antibodies. Lancet 1%7;2: 1105. 12. Bernstein IL, Perara M, Gallagher JS, Michael C, Johansson SGO. In vitro cross allergenic&y of major aeroallergenic pallens by the radiilergosorbent technique. J ALLBRGY m IMMUNOL 1975;56:323. 13. Frankland AW, Ltmn JA. Asthma caused by tbe grain weevil. Br J Ind Med 1%.5;22:157-9. 14. Burge PS, Edge G, O’Brien IM, Harries MC, Hawkins R, Pepys J. Occupational a&ma in research center breeding locusts. Clin Allergy 1%0;10:355-63.
and Dayton,
er, Ph.D.,
Ohio
Six laboratory workers who were exposed to American cockroaches (AC) and German cockroaches (GC) while they were pe$orming immunologic experiments were evaluated for cockroach hypersensitivity. Prick skin testing and UAST were performed with whole body extracts (I :20 wtlvol) of AC, brown-banded (BB), and GC species as well as hemolymph and fecal (F) extracts of AC. Three of six workers reported work-related nasal and ocular symptoms associated with xenografting and bleeding of cockroaches. All three symptomatic workers exhibited cutaneous reactivity to at least one cockroach antigen. Elevated RAST binding was observed in one of the three symptomatic workers. A nasal provocation to AC was positive in the most symptomatic worker at a provocative dose of 3.2 X IO’-’ mg causing a 50% decrease of nasaljow rate from baseline. After pretreatment with nasal cromolyn, the provocative dose causing a 50% decrease from baseline increased to 2.6 X IO-’ mg. Nasal provocation with the same concentrations of AC were negative in two skin test negative subjects. RAST-inhibition studies demonstrated cross inhibition of the serum-spec$c IgE binding to AC-hemolymph by AC, GC, and BB whole body extracts. However, specific IgE binding to AC-F was inhibited by AC-F and AC but not by GC or BB whole body extracts, suggessting there was greater specificity of the F allergens. This study demonstrated that cockroach allergens elicit IgE-dependent upper respiratory sensitization in the workplace. (J ALLERGY CLIN IMMUNOL
1987;80:586-90.)
Cockroach emanations have been recognized as important inhalant allergens. ’ The most common cockroach species in North America are the GC (Blatella germanica) and the AC (Periplaneta americana). In 1964, Bernton and Brown’ demonstrated direct cutaneous sensitivity and positive Prausnitz-Kiistner responses to cockroach allergens. Subsequent studies have also documented respiratory sensitization to cockroach allergens.3-‘0Kang and Sulit” noted a high prevalence of cutaneous reactivity to cockroach allergens among urban patients with asthma. The same
Abbreviations
AC: H: BB: GC: F: PD,:
used
Americancockroaches Hemoiymph Brown-bandedcockroaches Germancockroaches Fecal Provocative doseof allergenrequiredto cause a decreaseof SO%of nasalflow rate from baseline
Tm: T&ebrio
molitor
investigators subsequently documented the presence
of both immediate- and dual-phase bronchoconstrictive responsesin patients with extrinsic asthma after bronchial challenge with cockroach allergen.3, 5 This article presents clinical and immunologic stud-
From the Division of Immunology, Department of Medicine, University of Cincinnati Medical Center, Cincinnati, and *Department of Bioiogical Sciences and F’bysioiogy, Wright State University, Dayton, Ohio. Received for publication Nov. 20, 1986. Accepted for publication April 18, 1987. Reprint requests: David I. Bernstein, M.D., University of Cincinnati MedicaI Center, Division of ImmunoIogy, M.L. #563, 231 Bethesda Ave., Cincinnati, Ohio 45267.
ies on cockroach-labora@ty workers, some of whom developed nasal and ocular Sykes assc&@ed with work-related exposure to cockroacbs and I@mediated sensitization to cockroach allergens.
Thestudygroupconsistedof six laboratoryworkersfrom the Departmentof BiologicalSciencesat the WniGersityof Cincinnatiwho were performingexperimental&&es on cockroaches and represented all the workers in the Iabomtory who wereregularlyexposedto AC agdGC. The workers reportedno other signific~t exposureto ctMzoac&es outside the workplace or at home. Exposureto feca&nat&al
VOLUME NUMBER
BfJ 4
Cockroach
sensitization
occurred in those workers who also participated in feeding and maintenance of cockroach colonies located in a separate storage room. There was further exposure to AC-H when animals were exsanguinated for in vitro cellular and humoral studies. In addition, xeno- and allografting experiments were performed with BB and GC. Because this laboratory was primarily involved with the investigation of cockroaches, none of the six workers had an opportunity for exposure to other laboratory animals. An informed consent was obtained from all subjects. An occupational history was obtained on all six workers by physicians. The duration of laboratory exposure and latency period before onset of symptoms was recorded. Information was elicited regarding possible work-related ocular, nasal, and bronchial symptoms. A complete personal and family atopic history was also obtained.
TABLE I. Results of symptoms, skin tests, and RAST in cockroach-exposed and nonexposed laboratory workers
Immunologic
NA
studies
Cutaneous prick testing was performed in all six exposed and eight IaboratoIy workers not exposed to cockroaches. Pure culture extracts of AC, GC, and BB whole bodies were prepared by Dr. Larry Arlian, Wright State University, Dayton, Ohio. Whole insect bodies were dried in a dessicator with anhydrous calcium sulfate for 48 hours and then extracted in phosphate-buffered saline, followed by sterilization through a Millipore filter (Millipore Corp., Bedford, Mass.).16 All skin test reagents were prepared at a final concentration of 1: 20 wt/vol. H and F extracts were prepared in a similar manner. Protein content was determined by the Bio-Rad (Bio-Rad Laboratories, New York, N. Y.) method with bovine gamma globulin as a reference protein. Prick testing was also performed with commercial extracts of dust mite, ragweed, grass, and cat allergens (HollisterStier Laboratories, Spokane, Wash.) to define atopic status. A prick test wheal that measured 3 mm greater than the saline control wheal accompanied by flare was considered a positive skin test. Specific IgE to cockroach allergens was measured by a modified RAST assay.” RAST results were expressed as percent binding calculated by dividing counts per minute bound by the worker’s serum by counts per minute of total 9-labeled anti-IgE added multiplied by 100. RAST-inhibition studies were performed with serum that exhibited the highest RAST binding to cockroach.” Equal volumes of test serum were incubated at 37” C for 2 hours with successive tenfold dilutions of each cockroach extract and centrifuged at 1500 X g for 15 minutes. The upper two thirds of the supematant was removed and incubated with AC-H coated and AC-F coated methylcellulose disks followed by the addition of ‘2SI-labeledanti-IgE. The percent of RAST inhibition was calculated as follows: 1 _ cpm bound by preabsorbed sample x 100 cpm bound by nonabsorbed sampleI [
Nasal-challenge
study
Dose-response nasal-provocation studies were performed with anterior rhinometry. A saline control challenge was performed before allergen challenge. The beginning dose
Worker
No.
1 2 3 4
5 6
Control subjects (N = 8)
Symptoms
Nasal, ocular, and palatal Nasal, ocular Nasal, ocular None None None None
Skin
test
587
RAST
Pos
Pos
Pos pas* pas* Neg Neg* Neg
Neg NA Pos Neg NA Neg
- not available because subjects refused venipuncture; pas = positive; neg = negative. *Cutaneousreactivity to inhalantaeroallergens.
was delivered by nasal instillation of 0.05 ml of solution containing 5 X loo3 mg based on weight per volume of the AC whole body extract. Nasal flow rate was measured before and after challenge with a Connell (Nasal Diseases Study Center, Englewood, N. J.) anterior rhinometer and expressed in milliliters per second at a constant inspiratory pressure of - 1.5 cm H,O. The same nostril was instilled every 5 minutes with increasing tenfold concentrations of AC until a positive response or a final concentration of 1.O mg/ml wt/vol was achieved. The best flow rate of three inspiratory maneuveF was recorded, and a fall in nasal patency of 50% from baseline saline control was considered a positive challenge. The cumulative PD,, was determined by extrapolation from a dose-response curve. Nasal challenges were also performed on two control subjects with no cutaneous reactivity to cockroach allergens.
RESULTS Clinical evaluation Three of the six laboratory workers described the immediate onset of nasal stuffiness, runny nose, and sneezing accompanied by ocular symptoms and itching associated with cockroach exposure (Table I). These symptoms primarily occurred during bleeding and xenografting experiments. None of the workers described wheezing, chest tightness, cough, or shortness of breath.. Of the three symptomatic workers, only one (No. 3) gave a prior atopic history consistent with ragweed and grass pollenosis and exhibited cutaneous reactivity to at least one inhalant aeroallergen. The mean latency period before onset of work-related symptoms was 6 months. The history of the most symptomatic worker (No. 1) is presented below. C. M., a 24-year-old white female research assistant,had worked in the laboratory with cockroaches for 1*/2years. Approximately 1 month after beginning work, she noted the
588
Steinberg
J. ALLERGY
et al.
CLIN. IMMUNOL. OCTOBER 1987
100 90 80 70 60 50 40 30 20 10
.OOl
.Ol
0.1 rngtml
InM&Wng
1.0 Protein
FIG. 1. RAST inhibition studies (worker No. 4) of specific IgE binding to AC-X d&s. Inhibition wss achieved by AC whole body and AC-H as well as whole body extracts of GC, BB cockroach. and a beetle species, Tm.
TAW$1. MST binding nonexposed workers
worker
No.
1 4
Control subjects
results
to various
cockroach
allergens
in two workers
AC whole body
AC-H
AC-F
6.0* 5.6* 2.5 r 0.35
2.8 8.6* 2.1 k 0.40
5.1* 10.1* 2.4 +- 0.60
and eight
2.6 6.2* 2.4 k 0.60
2.5 1.7 2.4 ” 0.40
(N = 8) *Significant RAST binding is 3 SD above the % of nonexposed control subjects; results presented in -C SEM.
immediate onset of ocular itching, nasal stuffiness,sneez-
ing, and pa&d itching while shewasfeedingand transporting cockroaches. These symptomswere alsonotedin the lahoratery whiie shewas performingexperimentson animahand resolvedcompletelylater at home,on weekends,andon vacation. Subsequent pretreatmentwith intranasalcrornolyn sodiumattenuatedher work-relatednasal andocularsymptoms.
There were four workers with cutaneousreactivity to eo&roa& a&@~. AII three symptomatic workers exhibited positive skin tests to one or more of the cockroach miqents (Table I). Although worker No. 4 was asympmmatic, he exhibited cutaneousreactivity to four of five cockroach allergens as well as common inb&ot aer&Iergens . One of three symptomatic ver-
SW two of three asymptomatic workers had positive skin teststo common inbahmt~~~~~e~~~~i~~nt with their personal atopic histories. Two or more cutaneo~ respor~ses to the ,~MMI of cockroach allergens were observed in the f&r -cutaneousreactors. Worker No. 1 exhibit& p&&e skin tests to all cockroach &lqps. Prick teets to CL+&-
roiich allergens were neg&ve in eight Iworkers not exposed to cockroaches. Two of four i~~Svi&ds with eutllllaaus ~~~t-rVity to cockrmh e?&ibixed (Table II) to cockmach W&XFS >3 SD above the mean of eight subjects. As presentedin T&@$I, hibited elevated RAST X-F (5. E%), W&err exhibited si~~t R&ST k&xdieg to &fiw of &vi
VOLUME NUMBER
80 4
Cockroach sensitization
533
100 90 60 70
AC-F
60 50 40 30 20
10 .Ol
1.0
0.1
mg/ml Inhibiting
Protein
PIG. 2. RAST inhibition studies (worker No. 4) of specific IgE binding to AC-F disks. Significant inhibition was achieved by AC whole body and AC-F but not by whole body extracts of GC, BB cockroach, and a beetle species, Tm.
130 120 110 100 e z 2
90
80
m”
70
5 I; = 2 ap
80 50 40
I
.OOl
.ch
(Cumulative
011 Doae
1.0
in mo)
Fig. 3. Nasal provocation challenge to AC whole body extract in worker No. 1. Graph shows the PDW expressed as the cumulative dose of antigen delivered to achleve’a 50% reduction in nasal airflow and the percent fall of nasal airflow from prechallenge baseline before treatment (~1 and after treatment (o--o ) with cromolyn.
cockroach allergens (AC, AC-H, AC-F, and GC). These responses in worker No. 4 could represent immunologic reactivity before onset of clinical sensitivity. RAST inhibition was performed on the serum of worker No. 4 with AC-F- and AC-H-coated allergen disks. As illustrated in Fig. 1, inhibition of RAST binding to H was achieved by all three cockroachbody extracts (AC, GC, and BB) as well as AC-F and
AC-H allergens. Inhibition was also obtained with a larval extract from the beetle Tm which belongs to a different insect order. Fig. 2 illustrates inhibition experiments on the same serum with AC-F-coated disks. There was no significant inhibition by the body extracts of GC, BB, or Tm. By contrast, there was good inhibition of RAST binding to F allergen by the homologous AC-F allergens and AC whole body but significantly less by AC-H.
590
Steinberg
J. ALLERGY
et al.
Nasal ehdsnge Nasal provocation with AC body extract was perforrned on worker No. 1 (C. M.) (Fig. 3). After instillation of AC extract, nasal patency fell 69.2% from baseline, at which ‘time the subject noted palatal itching and sneezing. The PD,, was 3.2 X low3 mg on the initial challenge. Two weeks later, the challenge was repeated after pretreatment with intranasal cromolyn. The PD,, increased to 2.6 X 10-l mg. Thus, cromolyn inhibited the nasal response to cockroach allergen. There was no significant variation from baseline after nasal provocation in two nonexposed subjects who lacked cutaneous reactivity to cockroach allergens. DJSWSSJON Previously, Bemton and Brown* reported occupational sensitization to cockroaches among entomologists and a laboratory worker. We have demonstrated work-related allergic rhinitis among invertebrate immunologists who were regularly exposed to cockroaches. Richman et aL8 reported that whole body, cast skin, egg casing, and fecal materials of the GC were allergenitally distinct by RAST-inhibition analysis. In this study, the least potent of these allergens was fecal material with whole bodies and cast skins sharing relatively, higher potencies. The same investigator found little cross-reactivity between the AC and GC extracts. In the present study, we have demonstrated that AC-H possess a broad range of cross-reactivity not only with AC-F ailergens but with a whole range of whole body allergens of different cockroach species. In addition, cross-reactivity was demonstrated between H of AC and a beetle larval antigen, Tm, of a different insect order. This finding could be due to a multiplicity of potential allergens contained in H that are common to various insect orders and species. The finding of RAST inhibition of AC-H by AC-F but lack of inhibition of AC-F by AC-H could also reflect nonspecific binding of multiple proteins to the complex AC-H. By contrast, the AC-F antigen system exhibited a more specific inhibition profile. Although AC-F allergens exhibited cross-reactivity with AC whole body allergens, there was no cross-reactivity
CLIN. IMMUNOL. OCTOBER 1987
with allergens of different species, thereby demonstrating a high specificity for F allergen. Laboratory workers have developed respiratory allergy to insects in other occupational settings.‘“. I4This study demonstrated the development of clinical sensitivity to whole body, F, and H cockroach allergens in the workplace. The clinical significance of these allergens in cockroach sensitization requires further investigation. Special thanks to Dr. Larry Arlian for preparing the cockroach extracts and to Ms. Jan Shulman for preparing this manuscript. -S 1. Kang B, Chang JL. Allergenic impact of inbaled arthropod material. Clin Rev Allergy 1985;3:363-75. 2. Bemton HS, Brown H. Insect allergy: preliminary studies of the cockroach. J AUERGY 1%4;35:%-13. 3. Kang B. Study on cockroach antigen as a p&able causative agent in bronchial asthma. J AUEROY CL@~~~NOL 1976; 58:357-65. 4. Twarog FJ, Picone FJ, S&u& RS, So J, Colten HR. immediate hypersensitivity to co&ma& isoiation and purification of the major antigens. J AUERCY CL~ hmura~ 1937,593154-60. 5. Kang B, Vellody D, Homburger H, Yunginger J. Cockroach cause of allergic asthma: its specilicity and immtlnologic profile. J AIJ.ERGYCLIN IMM~?NOL1979$3:X)-6. 6. Hulett A, Do&horn R. House dust mite and cockroach allergy in a midwestem population. Ann Allergy 1979;42:160-5. 7. Fraser BN. Cockroaches in reiation to bronchial asthma in the Durban area. S Afr Med 1979$5:637-S. 8. Ricbman P, Khan HA, lkkek$ub PC, et al. The impMtant sources of German cockroach aikgens asdetermined by RAST analyses. J ALLER~V CL~ b&mm~ &4;73:59@5. 9. Chang JL, Ryo UY, Kang B. Changes in free histamine in peripheral circulation following cockroach aatigen chalIenge in asthmatics. Mt Sinai 3 Med I984:51:197-202. 10. Kang B, Sulit N. A comparative study of prevalence of skin hypersensitivity to cockroach and house dust antigens. Ann Allergy 1978;41:333-6. 11. Wide L, Ben&h H, Johansson SGO. Diagnosis of allergy by an in vitro test for allergen antibodies. Lancet 1%7;2: 1105. 12. Bernstein IL, Perara M, Gallagher JS, Michael C, Johansson SGO. In vitro cross allergenic&y of major aeroallergenic pallens by the radiilergosorbent technique. J ALLBRGY m IMMUNOL 1975;56:323. 13. Frankland AW, Ltmn JA. Asthma caused by tbe grain weevil. Br J Ind Med 1%.5;22:157-9. 14. Burge PS, Edge G, O’Brien IM, Harries MC, Hawkins R, Pepys J. Occupational a&ma in research center breeding locusts. Clin Allergy 1%0;10:355-63.